"Certainly no brand army is going have support of the administration in London - and we won't be making any efforts to enforce it ourselves."

He likened the "brand army" to the "Grand Army" which was assembled by Napoleon for the invasion of Britain - which never took place.

Branding is not just an issue for the Olympic Movement, but for the sponsors of the Games as well.

The organisers have been attempting to clarify their restrictions after the head of the London Games suggested a shirt bearing the logo of Pepsi - the arch-rival of Olympic sponsor Coca-Cola - would probably be banned from Olympic venues.

Pepsi - no friend of arch-rival and Olympic sponsor Coca-Cola

"No, you probably wouldn't be walking in with a Pepsi T-shirt because Coca-Cola are our sponsors," said Lord Coe.

"They have put millions of pounds into this project, but also millions of pounds into grass roots sport. It is important to protect those sponsors."

But Locog, the organising committee that Lord Coe heads, denied that was the case.

"Any individual coming into our venues can wear any item of clothing, branded or otherwise," the committee said in a "mythbuster" fact sheet.

However it did admit there could be a problem "if large groups come in together wearing clearly visible branding/marketing".

It said that could be classed as "ambush marketing" by non-sponsors - which would be a definite no-no.

Organisers want to head off stunts like the one at the 2010 World Cup in South Africa, when the Bavaria brewing company outfitted some 30 Dutch women in mini-dresses in its trademark orange for the Netherlands' opening game against Denmark.

Adidas is another big sponsor, but Lord Coe said visitors wearing Nike trainers would "probably" be allowed in.

And the organising committee insisted Nike shoes are definitely OK for spectators to wear - but not necessarily for Games staff or participants.

Guidelines sent to children who will be forming a guard of honour for the athletes' parade on July 27 have been advised to wear "unbranded or Adidas shoes".

The confusion follows a swirl of rumours about the event's complex commercial rules, including reports of visitors to the Olympic Park being forced to carry their crisps in a clear plastic bag because the brand was not an Olympic sponsor.

Locog insisted that was another Olympic myth.

Nevertheless, advertising is banned in "event zones" around the Olympic venues, and hundreds of uniformed officers are being dispatched during the July 27 to August 12 games to look for infractions.